A LIMPOPO police constable allegedly shot and killed his wife and her mother in what is said to have been a domestic dispute involving a child custody battle.

Police said the suspect fired shots at his wife, Nyambeni Murigwathoho, 29, and his mother-in-law, Mbengeni Murigwathoho, 47, at Tshivhilidulu village near Thohoyandou before taking his son and surrendering himself to the police at Siloam.

Nyambeni was allegedly shot seven times. Her mother was shot in the chest while trying to escape. Another bullet struck her in the back.

The couple allegedly quarreled over child custody after they separated last Monday.

Siloam police spokesperson Warrant Officer Livhuwani Nefale said the suspect had an argument with his wife last week and she was forced out of the couple's home in the village.

"We discovered that he used his service pistol in the shootings," Nefale said.

He said an investigation was under way to find out what triggered the shootings. Domestic violence is thought to be the cause.

It is alleged that the man, after killing the victims, walked around the village boasting that he had killed the two. He proceeded home with his son.

Neighbours said they were shocked by gunfire and screaming at the deceased's house. They hid themselves when they saw the gun-totting man moving out of the house.

They said after a few minutes when they got into the house they saw Mbengeni's lifeless body lying on the floor.

The officer has been charged with two counts of murder.